Comprehensive Cryogenic Characterizations of a Commercial 650 V GaN HEMT

Gallium nitride (GaN) high-electron-mobility transistor (HEMT) is regarded as the most promising candidate for cryogenic power electronics applications. In this article, comprehensive cryogenic characterizations have been performed for a commercial 650 V GaN HEMT to demonstrate its advantages and possible issues. The static characterizations, including on-state resistance and threshold voltage are performed. Moreover, the dynamic characterizations are conducted by using a double pulse test (DPT) approach, where the device turn-on and turn-off times, turn-on and turn-off switching losses are recorded under different temperatures. Lastly, the dynamic on-state resistance performance for GaN HEMT is also investigated by using a clamping circuit. The results indicate that: 1) the on-state resistance can achieve around 70% reduction at 93 K; 2) the device threshold voltage is reduced slightly; 3) the turn-on switching time is reduced under low temperatures with an increased turn-on dv/dt and di/dt; 4) the turn-off switching time is relative stable over the temperature range; 5) the device switching loss is reduced due to the improved switching speed; 6) the dynamic on-state resistance of the evaluated GaN HEMT also shows a significant reduction at low temperatures.